28-06-2013, 03:59 PM
Steganography With Region Based on Matching Method
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INTRODUCTION
The hide a message, open a bitmap file, then enter a password or select a key file. The key file can be any file or another bitmap. This password or key will be treated as a stream of bytes specifying the space between two changed pixels. I don't recommend text files, because they may result in a quite regular noise pattern. The longer your key files or password is the less regular the noise will appear.
Next step, enter the secret message or choose a file, and click the Hide button. The application writes the length of the message in bytes into the first pixel. After that it reads a byte from the message, reads another byte from the key, and calculates the coordinates of the pixel to use for the message-byte. It increments or resets the color component index, to switch between the R, G and B component. Then it replaces the R, G or B component of the pixel (according to the color component index) with the message-byte, and repeats the procedure with the next byte of the message. At last, the new bitmap is displayed. Save the bitmap by clicking the Save button. If the grayscale flag is set, all components of the color are changed. Grayscale noise is less visible in most images. The goal of steganography is to hide messages inside other harmless messages in a way that does not allow any enemy to even detect that there is a second secret key present. Steganography includes a vast array of techniques for hiding messages in a variety of media. Among these methods are invisible inks, microdots, digital signatures, covert channels and spread-spectrum communications. Today, thanks to modern technology, steganography is used on text, images, sound, signals, and more. To extract a hidden message from a bitmap, open the bitmap file and specify the password or key you used when hiding the message. Then choose a file to store the extracted message in (or leave the field blank, if you only want to view hidden Unicode text), and click the Extract button. The application step through the pattern specified by the key and extracts the bytes from the pixels. At last, it stores the extracted stream in the file and tries to display the message. Don't bother about the character chaos, if your message is not a Unicode text. The data in the file will be all right. This works with every kind of data, you can even hide a small bitmap inside a larger bitmap. If you are really paranoid, you can encrypt your files with PGP or GnuPG before hiding them in bitmaps. Now a days, various modes of communication like LAN, WAN and INTERNET are idely used for communicating information from one place to another around the lobe.
Information security
Information Security Attributes: or qualities, i.e., Confidentiality, Integrity and Availability (CIA). Information Systems are decomposed in three main portions, hardware, software and communications with the purpose to identify and apply information security industry standards, as mechanisms of protection and prevention, at three levels or layers: physical, personal and organizational. Essentially, procedures or policies are implemented to tell people (administrators, users and operators)how to use products to ensure information security within the organizations.
History
Since the early days of writing, heads of state and military commanders understood that it was necessary to provide some mechanism to protect the confidentiality of written correspondence and to have some means of detecting tampering. Julius Caesar is credited with the invention of the Caesar cipher ca. 50 B.C., which was created in order to prevent his secret messages from being read should a message fall into the wrong hands. World War II brought about much advancement in information security and marked the beginning of the professional field of information security.
The end of the 20th century and early years of the 21st century saw rapid advancements in telecommunications, computing hardware and software, and data encryption. The availability of smaller, more powerful and less expensive computing equipment made electronic data processing within the reach of small business and the home user. These computers quickly became interconnected through a network generically called the Internet.
Basic principles
Key concepts
For over twenty years, information security has held confidentiality, integrity and availability (known as the CIA triad) to be the core principles of information security. There is continuous debate about extending this classic trio. Other principles such as Accountability have sometimes been proposed for addition – it has been pointed out that issues such as Non-Repudiation do not fit well within the three core concepts, and as regulation of computer systems has increased (particularly amongst the Western nations) Legality is becoming a key consideration for practical security installations.
In 1992 and revised in 2002 the OECD's Guidelines for the Security of Information Systems and Networks proposed the nine generally accepted principles: Awareness, Responsibility, Response, Ethics, Democracy, Risk Assessment, Security Design and Implementation, Security Management, and Reassessment. Building upon those, in 2004 the NIST's Engineering Principles for Information Technology Security proposed 33 principles. From each of these derived guidelines and practices. In 2002, Donn Parker proposed an alternative model for the classic CIA triad that he called the six atomic elements of information. The elements are confidentiality, possession, integrity, authenticity, availability, and utility. The merits of the Parkerian hexad are a subject of debate amongst security professionals.
Confidentiality
Confidentiality is the term used to prevent the disclosure of information to unauthorized individuals or systems. For example, a credit card transaction on the Internet requires the credit card number to be transmitted from the buyer to the merchant and from the merchant to a transaction processing network. The system attempts to enforce confidentiality by encrypting the card number during transmission, by limiting the places where it might appear (in databases, log files, backups, printed receipts, and so on), and by restricting access to the places where it is stored. If an unauthorized party obtains the card number in any way, a breach of confidentiality has occurred.